Final Submittal Source Evaluation Project Activities€¦ · Subject: Final Submittal ‐ Source Evaluation Project Activities for Middle Santa Ana River, TMDL Program Support 2010‐2011

Final Submittal Source Evaluation Project Activities.docx

Memorandum To: Rick Whetsel, SAWPA From: CDM Date: September 30, 2011 Subject: Final Submittal ‐ Source Evaluation Project Activities for Middle Santa Ana

River, TMDL Program Support 2010‐2011

In 2010, the Middle Santa Ana River (MSAR) Task Force identified five source evaluation project activities for execution during the 2010‐2011 fiscal year. As directed by the Task Force, CDM prepared a scope of work for each proposed study activity so that they could be further evaluated for implementation. Following review by the Task Force and concurrence by the Santa Ana Regional Water Quality Control Board (letter dated December 7, 2010), the Task Force directed CDM to proceed with the planned source evaluation activities in spring/early summer 2011.The results of these studies are presented in the following technical memoranda organized as follows:

Attachment A, Box Springs Channel Follow-up Study (Task 2.1) ‐ Short‐term bacterial indicator study at the Box Springs Channel site originally sampled as part of the Urban Source Evaluation Plan (USEP) Monitoring Program in 2007‐ 2008. During that sample period, human source bacteria were regularly detected and high bacterial indicator concentrations were present. Following a local investigation in 2008, a sanitary/storm sewer cross connection was identified and corrected. The purpose of the task was to conduct follow‐up sampling activity to evaluate current bacterial indicator levels and verify that human source bacteria are no longer present.

Attachment B, Preliminary Characterization of Bacteria Loading from MS4 in Pomona and Claremont (Task 2.2) ‐ When the USEP program was implemented in 2007‐2008 no samples were collected from sites representing the Cities of Pomona and Claremont. The purpose of this task was to gather dry weather condition bacterial indicator data during the dry season to provide a preliminary characterization of potential bacteria loading and presence/absence of human sources of bacteria from this portion of the MSAR watershed.

Attachment C, Survey of Dry Weather Flows from MS4 Outfalls to Major Tributaries (Task 2.3) ‐ The purpose of this source evaluation study was to gain additional information regarding the

Rick Whetsel, SAWPA September 30, 2011 Page 2

Final Submittal Source Evaluation Project Activities.docx

variability of dry weather flows in stormwater channels/outfalls in the MSAR watershed. The information gained from this effort, combined with other available dry weather flow data, support characterizations of typical dry weather flows in the area and support compliance analyses in the Comprehensive Bacteria Reduction Plan (CBRP).

Attachment D, Calculate Mass Balance for Dry Weather Conditions (Task 2.4) ‐ The purpose of this task is to quantify, to the extent possible, the mass balance of bacterial indicators under dry weather conditions based on known dry weather hydrology, source of flow, and available bacteria concentration data. Mass balance characterizations are an important element of the compliance analysis contained within the CBRP.

Attachment E, Calculate Site-Specific Log Standard Deviation at Monitoring Sites (Task 2.5) ‐ The EPA uses a default log standard deviation (LSD) of 0.4 for E. coli when calculating single sample maximum criteria. A site‐specific LSD may be substituted for the default value where such data exist, which would result in different single sample maximum criteria. The potential to use site‐specific LSD to establish site‐specific single sample criteria has been incorporated into the Basin Plan amendment under development by the Stormwater Quality Standards Task Force. The purpose of this task was to calculate LSD values for the USEP and Watershed‐wide Compliance monitoring sites.

Attachment A

Box Springs Channel Follow-up Study (Task 2.1)

Memorandum To: Rick Whetsel, SAWPA From: Richard Meyerhoff, CDM Thomas Lo, CDM Date: September 30, 2011 Subject: Technical Memorandum ‐ Box Springs Channel Follow‐up Study, 2011 Dry

Season

Purpose The Box Springs Channel site was originally sampled as part of the Urban Source Evaluation Plan (USEP) Monitoring Program in 2007‐2008. During that sample period, human source bacteria were regularly detected and high bacterial indicator concentrations were present. Following a local investigation in 2008, a sanitary/storm sewer cross connection was identified and corrected. During the 2011 dry season, Riverside County Flood Control & Watershed Conservation District (RCFCWCD) staff in coordination with CDM conducted a 5‐week follow‐up study to evaluate current bacterial indicator levels and verify that human source bacteria are no longer present. This technical memorandum reviews past USEP sample results and presents the results from recent sampling during the 2011 dry season.

Description of Box Springs Channel Site Box Springs Channel drains a 31 square mile urbanized subwatershed in the City of Riverside. Dry weather flows measured in this channel are approximately 3.2 cfs (average of USEP field measurements in dry season 2007) and may consist of a combination of nuisance flow from urban drainages in the City of Riverside and de minimus water from Riverside Public Utilities (RPU). This channel may be divided into two segments:

Upstream channel – Engineered section with 0.15 mile vertical‐wall concrete‐lined channel; 0.10 mile trapezoidal rock‐lined slope with natural bottom

Downstream Channel – 0.4 mile natural segment that confluences with the Middle Santa Ana River.

The Box Springs Channel USEP site was identified very early in the 2007‐2008 USEP Monitoring period as having elevated fecal coliform and E. coli concentrations and strong indications of

Rick Whetsel July 26, 2011 Page 2

possible contamination from human sources. RCFCWCD initiated an IC/ID investigation in January 2008 to attempt to identify the source of the bacteria.

Coincidentally, during the same time, the City of Riverside was also reviewing plans to replace a sewer line running near Box Springs Channel. While performing dye tests on lateral sewer lines, the City discovered a single restroom toilet, located in the Sam Evans Sports Complex on the Riverside Community College (RCC) Riverside Campus, was inadvertently connected to a storm drain pipe rather than a sewer line. To correct the problem, the cross‐connected toilet was removed in May of 2008 and the sewer lateral was later capped to prevent any recurrence.

On May 6 and June 30, 2008, two separate samples analyzed by the Orange County Water District were both negative for the presence of human source bacteria. However, in September of 2008, a sample collected from Box Springs Channel indicated the probable presence of low levels of human bacteria.

Previous USEP Monitoring Results The 2007‐2008 USEP results indicated elevated geomean bacterial indicator concentrations and the common presence of human source bacteria (Table 1). The observed concentrations exceeded existing Basin Plan fecal coliform objectives and proposed E. coli objectives.

Table 1. Bacterial Indicator Data Summary for Box Springs Channel, 2007 Dry Season

Parameter

Geometric Mean Dry Season 2007

Week of 7/14 to Week of 8/11

Week of 9/1 to Week of 9/29

Fecal coliform 12,990 23,077

E. coli 1,149 4,793

Human Source Bacteroides Present 5 of 5 samples Present 5 of 5 samples

Box Springs Channel Follow‐up Study Results From April 19 to June 24, 2011, RCFCWCD staff in coordination with CDM sampled Box Springs Channel, collecting data for field parameters, bacterial indicator concentrations, and presence/absence of human source bacteria (Tables 2, 3 and 4). Water quality parameters were collected five consecutive weeks. Flow data were gathered for five additional weeks1.

1 Additional flow data were gathered to support other ongoing source evaluation studies to improve dry weather flow estimates in the area.


Table 2. Water Quality Parameters and Flow Results

Sample Date Temp (°C) Turbidity (NTU)

Conductivity (µS/cm)

Dissolved Oxygen (mg/L)

pH Flow (cfs)

04/19/2011 17.08 59.201 520 9.41 7.90 3.2

04/27/2011 17.92 1.10 569 9.06 7.75 0.5

05/03/2011 18.57 0.87 562 9.06 7.87 1.2

05/11/2011 17.7 0.9 680 9.45 8.02 1.5

05/19/2011 15.8 35.11 748 9.45 8.03 3.3

5/24/2011 1.17

6/2/2011 NR2

6/9/2011 3.66

6/14/2011 2.70

6/24/2011 0.50

Mean Flow 2.2

1 Pipeline construction activity near Box Springs channel may be source of elevated turbidity readings. 2 NR (no reading) due to flow meter equipment malfunction

Table 3. Box Springs Channel Bacterial indicator Results

Date Fecal Coliform (cfu/100 mL) E. coli (cfu/100 mL)

4/19/2011 540 780

4/27/2011 770 990

5/3/2011 3,900 2,100

5/11/2011 2,400 2,000

5/19/2011 900 1,400

Geomean 1,285 1,353


Table 4. Results of Analyses for Presence/Absence of Bacteroides at Box Springs Channel

Sample Date Human Marker:

(Presence/Absence of Bacteroides)

4/19/11 Absent

4/27/11 Absent

5/3/11 Absent

5/11/11 Absent

5/19/11 Absent

Study Findings Sample results indicate significant reductions in the geometric mean of fecal coliform observed in summer 2007 as compared to what was observed in 2011. E. coli concentrations were similar when compared to one 2007 sample period (July‐August 2007), but lower when compared to the other (September 2007) (see Table 1). Regardless, the observed geometric mean concentrations in 2011 are well above existing or proposed Basin Plan water quality objectives for bacterial indicators.

Results from Bacteroides analyses indicate that no human bacteria were present in the water samples collected in 2011. This finding further supports the presumption that the cross‐connection discovered during the IC/ID investigation in January 2008 was the source of the human bacteria detected during 2007‐2008 USEP monitoring.

Attachment B

Preliminary Characterization of Bacteria Loading from MS4 in Pomona and Claremont (Task 2.2)

Memorandum To: Rick Whetsel, SAWPA From: Richard Meyerhoff, CDM Thomas Lo, CDM Date: August 12, 2011 Subject: Preliminary Characterization of Bacteria Loading from MS4 in Pomona and

Claremont

Background The Santa Ana Regional Water Quality Control Board (RWQCB) adopted and the State Water Resources Control Board (SWRCB) approved the Middle Santa Ana River (MSAR) Bacterial Indicator TMDL to address fecal indicator bacteria (FIB) impairments in 1995. After EPA Region 9 approval, the MSAR Bacteria TMDL took effect on May 16, 2007. The MSAR Bacterial Indicator TMDL required urban and agricultural dischargers to implement a watershed‐wide bacterial indicator monitoring program by November 2007.

The MSAR dischargers worked collaboratively through the MSAR Watershed TMDL Task Force (TMDL Task Force) to develop this program. As part of the MSAR Bacteria TMDL implementation, five Watershed‐wide compliance monitoring program locations have been monitored since July 2007 for bacterial indicators.

In addition, the SWRCB funded a 2006 Proposition 40 Grant for San Bernardino County and Riverside County MS4 Permittees to support implementation of TMDL requirements. With this Grant 40 funding, the Permittees, in collaboration with SAWPA and the MSAR TMDL Task Force, implemented an Urban Source Evaluation Plan (USEP) Monitoring Program in 2007 to characterize urban bacteria sources within the MSAR watershed.

It was recognized at the time of the 2007 USEP Monitoring that the Chino Basin subwatershed portion of the MSAR watershed included potential MS4 discharges from jurisdictions outside of the San Bernardino County MS4. These jurisdictions include the Cities of Claremont and Pomona, which are located within Los Angeles County and thus not under the jurisdiction of the Santa Ana RWQCB. Since the completion of the USEP Monitoring Program, the Cities of Claremont and Pomona have since joined and participated in the TDML Task Force.

Rick Whetsel August 12, 2011 Page 2

Based on monitoring data from the Watershed‐wide Compliance Monitoring Program and USEP Monitoring Program, San Bernardino and Riverside County MS4 Permittees have each developed a long term dry weather Comprehensive Bacteria Reduction Plan (CBRP) designed to achieve TMDL compliance under dry weather conditions.

Purpose When the USEP program was implemented in 2007‐2008, no samples were collected from sites representing the Cities of Pomona and Claremont. This memorandum summarizes the steps taken by CDM and the TMDL Task Force in Spring 2011 to identify new urban source evaluation sample sites specifically representing potential dry weather MS4 discharges from Pomona and Claremont. This monitoring effort collected bacterial indicator data as well as analyzed for presence/absence of human source bacteria (Bacteroides). Newly gathered data provide a preliminary characterization of bacteria loading in dry weather conditions from this Chino Creek portion of the MSAR watershed and will further guide implementation of the CBRP. Site Identification Process CDM collaborated with staff from the Cities of Claremont and Pomona to identify MS4 outfalls to collect dry weather flow samples representing runoff from each City’s jurisdiction. The following section describes the steps taken with both City staff to identify potential outfalls for monitoring during the 2011 dry season.

Figure 1 shows the Chino Creek watershed‐wide compliance drainage area and identifies the locations where there has been past and ongoing sampling within the Chino Creek watershed‐wide drainage area. Figure 1 also shows the location of the Cities of Claremont and Pomona in relation to the Chino Creek watershed‐wide compliance drainage area.


Chino Creek Watershed‐wide Drainage Area Figure 1


Claremont MS4 Sample Location CDM contacted Craig Bradshaw, City of Claremont City Engineer, to identify MS4 outfalls discharging to the San Antonio Channel, which is tributary to Chino Creek. The City of Claremont reviewed their MS4 drainage system and identified a single storm drain line routing predominantly through Claremont before connecting to San Antonio Channel, located just south of Arrow Highway at San Antonio Channel. Figure 2 shows an aerial view of the location of this potential MS4 outfall in relation to San Antonio Channel and Montclair Basin, located east of San Antonio Channel. Montclair Basin No. 1 is one of a series of four basins owned by Chino Basin Water Conservation District and maintained and operated by Inland Empire Utilities Agency (IEUA) and Chino Basin Watermaster (CBWM). IEUA and CBWM are co‐permit holders for the Chino Basin Recycled Water Groundwater Recharge Program.

CDM conducted field verification at San Antonio Channel and observed that the storm drain outfall (see Figures 3 and 4) at Arrow Highway is not directly connected with an outlet to San Antonio Channel but rather has a permanent structural diversion to Montclair Basin No. 1 (see Figure 5). All dry and wet weather flows are diverted completely to Montclair Basin No.1 and bypasses San Antonio Channel.

In addition to this outfall diversion at Arrow Highway, San Antonio Channel also has an in‐channel automated inlet located just south of Arrow Highway (see Figure 6), which also diverts dry and wet weather flows to Montclair Basin No. 1. A second automated inlet is also constructed within San Antonio Channel and is located approximately 3 miles south of Arrow Highway, between Brook Street and State Street. This second automated inlet diverts all dry and wet weather flows within San Antonio Channel to Brooks Street Basin (Brooks Basin). Brooks Basin is also part of the Chino Basin Recycled Water Groundwater Recharge Program and is located approximately 0.15 miles east of San Antonio Channel and south of Brooks Street.1

With installation of an outfall flow diversion and two in‐channel automated inlets within San Antonio Channel as part of the Chino Basin Recycled Water Groundwater Recharge Program, all dry and wet weather flows within San Antonio Channel from Arrow Highway south to State Street are diverted completely to either Montclair Basins or Brooks Basins. In discussions with Andy Campbell, IEUA Groundwater Recharge Coordinator, CDM confirmed that any water transfers that utilize San Antonio Channel as a conveyance are coordinated with IEUA for closure of automated inlets within San Antonio Channel.2

1 Conversation with Ben Pak, Senior Engineer, Chino Basin Watermaster, March 28, 2011. 2 Conversation with Andy Campbell, IEUA Groundwater Recharge Coordinator, July 28, 2011.


Arrow Highway

Automated Inlet

Proposed Outfall

Montclair Basin No.1

San Antonio Channel

Figure 2

Aerial of Proposed MS4 Sampling Outfall at San Antonio Channel and Arrow Highway

Figure 3 MS4 Outfall (no outlet) to San Antonio Channel


Figure 4 View of San Antonio Channel adjacent to Proposed Outfall (no outlet in wall)

Automated Inlet located within San Antonio Channel Diverts Dry and Wet Weather Runoff to Montclair Basin No.1

Figure 6

Outfall Diversion Structure to Montclair Basin No.1 Figure 5


After eliminating the Arrow Highway outfall as an option for sampling (due to its permanent structural diversion to Montclair Basin #1), CDM conducted additional field observations to locate any other viable outfall within Claremont to the San Antonio Channel. From a desktop GIS review of MS4 mapping data, a potential outfall was identified on the west side of San Antonio Channel located at Moreno Street, located within the City of Montclair. CDM conducted further field verification and observed no existing outfalls at Moreno Street. Based on these field observations, CDM and Claremont staff concluded there are no existing outfalls to monitor for dry weather runoff in San Antonio Channel.

Pomona MS4 Sample Location CDM coordinated with Meg McWade, City of Pomona Utility Facilities Manager, to identify a sample location that would be representative of runoff draining predominantly City of Pomona jurisdictional areas. The City and its consultant team previously conducted a field survey in mid‐2010 to identify potential sample locations. The three identified locations included two along Chino Creek (upstream of San Antonio Channel) and one site within San Antonio Channel. The three potential MS4 outfalls sites (see Figure 7) included:

Location 1: Chino Creek near Market Place and South Garey Avenue

Location 2: Chino Creek near Towne Avenue

Location 3: San Antonio Channel at East County Road

Based on field verifications and desktop GIS review of MS4 mapping, CDM determined with concurrence from the City’s Consultant, Charles Abbot Associates, that the sample location to best represent and capture dry weather MS4 discharges from the City of Pomona was a sample location within Chino Creek just upstream of its confluence with San Antonio Channel (see Figure 8). Flows within the Chino Creek channel at this location capture discharges from MS4 lines running south through the City of Pomona collecting South Garey Avenue and Towne Avenue before discharging to Chino Creek. The approximate drainage area is 6,036 acres.


Figure 7Location of Potential Pomona MS4 Outfall Sites

Chino Creek

Location 1

Location 2

Location 3

San Antonio Channel


Previous Monitoring Results within Chino Creek Watershed Samples have been collected during dry weather seasons at the Chino Creek Watershed‐wide Compliance Site drainage area since 2007. The sites include:

Watershed‐wide Compliance Monitoring ‐ Chino Creek at Central Avenue (WW‐C7) has been monitored during each dry season from 2007 to 2011.

Two USEP Monitoring Program locations monitored in the 2007 dry season:

- San Antonio Channel at Walnut Ave (US-SACH)

- Carbon Canyon Creek Channel at Pipeline Avenue (US-CCCH)

Table 1 summarizes the results from the Water‐wide Compliance site (WW‐C7) for bacterial indicator concentrations during dry seasonal periods from 2007 through 2011. For comparative purposes, previous sampling results are summarized for the monthly time periods (where

Figure 8Chino Creek Sample Location (US‐CHINOCRK) Located Upstream of San Antonio Channel

San Antonio Channel

Sample Location

Chino Creek

Riverside Drive


available) closest to the time period in which the 2011 Source Evaluation Study was conducted (April to June).

Table 1. Watershed‐wide Compliance Monitoring Results at Chino Creek at Central Ave (WW‐C7), cfu/100mL


July ‐ Aug 2007

N 5 5

Median 3000 940

Range 1,500 to 5,900 560 to 2,700

May ‐ Jun 2008

N 7 7

Median 590 350

Range 200 to 3,200 210 to 610

May ‐ Jun 2009

N 6 5

Median 215 130

Range 70 to 280 40 to 230

May ‐ Jun 2010

N 7 7

Median 360 220

Range 40 to 1,500 90 to 410

May ‐ Jun 2011

N 7 7

Median 240 230

Range 150 to 4,800 170 to 2,700


Table 2 summarizes the results from the USEP Monitoring Program sites located within the Chino Creek drainage area.

Table 2. Summary of USEP Monitoring Program Sample Results for Dry Season 2007

Date Fecal coliform (cfu/100 mL) E. coli (cfu/100 mL) Human Source

Bacteroides Result Geomean Result Geomean

San Antonio Channel at Walnut Ave (US‐SACH)

7/12/2007 NS ‐‐ NS ‐‐ NS

7/18/2007 140 ‐‐ 80 ‐‐ ND

7/25/2007 5900 ‐‐ 40 ‐‐ ND 8/1/2007 2300 ‐‐ 610 ‐‐ ND 8/8/2007 8700 n/a1 920 n/a1 ND 8/28/2007 9000 ‐‐ 300 ‐‐ ND 9/4/2007 8000 ‐‐ 830 ‐‐ ND 9/11/2007 16000 ‐‐ 1200 ‐‐ ND 9/18/2007 4000 ‐‐ 320 ‐‐ ND 9/25/2007 13000 9,026 2000 718 ND

Carbon Canyon Creek Channel at Pipeline Ave (US‐CCCH) 7/11/2007 100 ‐‐ 9 ‐‐ ND 7/17/2007 290 ‐‐ 150 ‐‐ ND 7/24/2007 100 ‐‐ 280 ‐‐ ND 7/31/2007 90 ‐‐ 50 ‐‐ ND 8/7/2007 120 126 9 44 ND 8/28/2007 140 9 ‐‐ ND 9/4/2007 400 170 ‐‐ ND 9/11/2007 160 90 ‐‐ ND 9/18/2007 90 110 ‐‐ ND 9/26/2007 1400 257 280 84 ND

NS ‐ no sample collected; site access issueND – non‐detect

1 – Insufficient data (results for only 4 of 5 weeks) to calculate geometric mean.

Chino Creek Channel Monitoring for Pomona MS4 Discharges Between April 19 and June 24, 2011, CDM conducted monitoring over a ten week dry weather period at Chino Creek (US‐CHINOCRK), just upstream of its confluence with San Antonio Channel (see Figure 1). Field parameters were measured on a weekly basis (see Table 3). Additionally, laboratory analyses were performed for bacterial indicator concentrations and also to test for the presence/absence of human source bacteria. Table 4 and 5 summarize the results for US‐CHINOCRK location.


Table 3. Summary of Field Parameter Data Observed at US‐CHINOCRK During 2011 Dry Season

Date Conductivity (µS/cm)

Dissolved Oxygen (mg/L)

pH (Standard Units)

Turbidity (NTU)

Water Temperature

(°C) Flow (cfs)

4/19/2011 947 14.57 7.99 2.81 18.29 1.12

4/28/2011 782 11.83 9.86 1.85 18.54 2.19

5/5/2011 996 11.15 9.89 1.51 18.84 2.02

5/12/2011 1,026 10.70 9.72 3.21 22.73 2.94

5/20/2011 882 10.44 10.03 3.50 17.47 1.70

5/24/2011 860 10.84 10.16 3.04 16.30 1.45

6/2/2011 941 9.97 9.98 5.33 19.69 1.52

6/9/2011 900 9.35 9.79 4.12 17.05 1.42

6/14/2011 969 9.73 9.54 5.44 21.38 1.42

6/24/2011 1,002 10.95 9.45 7.43 23.38 1.18

Table 4. Summary of Bacterial Indicator Results Observed at US‐CHINOCRK During 2011 Dry Season


Result Geomean Result Geomean

4/19/2011 370 ‐ 160 ‐

4/28/2011 60 ‐ 80 ‐

5/5/2011 510 ‐ 1510 ‐

5/12/2011 1280 ‐ 970 ‐

5/20/2011 480 370 1290 475

5/24/2011 440 383 390 568

6/2/2011 550 597 410 787

6/9/2011 800 653 1000 725

6/14/2011 570 556 670 673

6/24/2011 950 637 750 604

Results for Human Source Bacteria Orange County Water District (OCWD) analyzed samples to determine the presence or absence of human source Bacteroides (see Table 5). In late April and early May, samples for two consecutive weeks showed presence of human source bacteria. On June 9th, a third sample showed presence of human source bacteria at very low concentrations.


Table 5. Presence/Absence for Bacteroides, US‐Chino Creek

Sample Date Human Marker:

Presence/Absence of Bacteroides 4/19/2011 Absent

4/28/2011 Present

5/5/2011 Present (at a very low concentration)

5/12/2011 Absent

5/20/2011 Absent

5/24/2011 Absent

6/2/2011 Absent

6/9/2011 Present (at a very low concentration)

6/14/2011 Absent

6/24/2011 Absent

Study Findings CDM worked with the Cities of Claremont and Pomona to identify urban source identification sampling locations to collect data to characterize dry weather MS4 discharges to the Chino Creek drainage.

No dry weather MS4 discharges from Claremont flow downstream within San Antonio Channel from Arrow Highway to State Street, since dry and wet weather flows are diverted to either the Montclair Basins or to Brooks Basins as part of the Chino Basin Recycled Water Groundwater Recharge Program, operated by IEUA and CBWM. Although no specific sampling location representing dry weather flows from Claremont MS4 discharges was identified for monitoring, a small portion of Claremont MS4 network connects to the Pomona MS4 network. Because of this inter‐connected MS4 network, dry weather discharges from Claremont to the Chino Creek watershed are still possible. The contribution of bacterial indicators from this area of Claremont was not evaluated as part of this study.

Dry weather samples collected at Chino Creek at upstream of San Antonio Channel represent flows from MS4 discharges from the City of Pomona. Bacterial indicator sample results were elevated for both fecal coliform and E. coli.

Results for Bacteroides analyses indicate that human source bacteria were present in three of ten water samples at the US‐CHINOCRK sample location.

Attachment C

Survey of Dry Weather Flows from MS4 Outfalls to Major Tributaries (Task 2.3)

Memorandum To: Rick Whetsel, SAWPA From: CDM Date: September 14, 2011 Subject: Source Evaluation Task 2.3 – Dry Weather Flows from MS4 Outfalls (2011

Dry Season)

Study Purpose In Spring 2011, the TMDL Task Force and CDM initiated dry weather flow (DWF) monitoring to enhance the existing DWF dataset for the Middle Santa Ana River (MSAR) watershed. The purpose of this study is to gain additional information to support updates to existing bacterial indicator source contribution analyses (see Technical Memorandum for Task 2.4, Calculate Mass Balance for Dry Weather Conditions). The new data will support characterization of DWF from MS4 outfalls not previously assessed and allow for analysis of the nature of DWF variability.

Flows exist in many MSAR waterbodies during dry weather conditions. Sources of flow include:

Tertiary treated effluent from Publicly‐Owned Treatment Works (POTWs)

Turnouts of imported water by the Metropolitan Water District (MWD) purchased for groundwater recharge by water agencies in the Santa Ana River watershed

Groundwater inputs from areas of rising groundwater

Temporary de minimus discharges, such as well blow‐offs

Water transfers between water agencies for conjunctive use programs

Authorized non‐stormwater discharges as defined by Waste Discharge Requirements issued by the Santa Ana Regional Water Quality Control Board (RWQCB)

Non‐permitted discharges including Phase 2 Municipal Separate Storm Sewer System (MS4) discharges.

Rick Whetsel September 14, 2011 Page 2

Within the MSAR watershed, many MS4 drainage areas do not typically cause or contribute to flow at downstream watershed‐wide compliance monitoring sites established under the MSAR Bacteria Total Maximum Daily Load (TMDL). DWF from these drainage areas is hydrologically disconnected from downstream waterbodies, by either (1) purposefully recharging groundwater in constructed regional retention facilities, or (2) through losses in earthen channel bottoms, where the recharge capacity of underlying soils exceeds dry weather runoff generated in upstream drainage areas.

Identification of Flow Monitoring Sites CDM worked with San Bernardino County Flood Control District (SBCFCD) and Riverside County Flood Control &Water Conservation District (RCFC&WCD) staff to select at least ten locations in the MSAR watershed to collect flow measurements for ten consecutive weeks under dry weather conditions from April to June 2011. CDM coordinated with SBCFCD and RCFC&WCD staff to finalize site selection after proposing a potential list of MS4 outfalls for field review.

Site selection considered factors such as where flow data are lacking, other data collection efforts ongoing or in the past, potential for the site to receive water transfers, and need for additional data for better understanding of hydrologic connectivity during dry weather conditions. Additional selection factors included outfall/channel physical constraints and any limiting factors that could hinder field staff from measuring or estimating flows.

Riverside County MS4 Outfall/Channel Locations Riverside County MS4 outfalls/channels considered for new or additional flow monitoring included those tributary to the Santa Ana River and Cucamonga Creek channel. CDM presented a list of potential MS4 outfalls or channels for flow monitoring. CDM and RCFC&WCD staff then conducted a field visit at each site on March 17, 2011, to gather additional information concerning presence of flow and connectivity to downstream waterbodies. Table 1 summarizes the observations recorded from the field visit.

Field staff also observed flow connectivity was often limited from MS4 outfalls tributary to the Santa Ana River (SAR), particularly where outfalls are located a significant distance from the SAR mainstem due to the changing course of the SAR.

Based on field observation, CDM and RCFC&WCD staff narrowed the list of flow monitoring sites to seven locations. Table 2 lists the seven sites selected for DWF monitoring (see also Figure 1).


Table 1. Potential Flow Monitoring Locations, Riverside CountyMS4 Outfall/Channel Flow Observation (March 17, 2011)

Tributary to Santa Ana River

Wilson Street Storm Drain No connectivity to SAR; flow was observed from outfall pipe but limited to area surrounding outlet structure; lots of standing water around structure

University Wash ‐Lake Evans Outlet No connectivity to SAR; slight flow exiting lake; appears to be a lake shutoff valve in a box

Outfall located just north of Mission Avenue and SAR

No connectivity – flow from the outfall proceeds along left bank of riverbed (~100 ft downstream of Mission Avenue Bridge overcrossing), but then ponds and infiltrates; SAR mainstem is located ~500’ to the west along the right bank

Box Springs Channel1 Observed flow connectivity to SAR mainstem; part of channel half covered with sand bar; flow depth is 5”‐6”

Magnolia Avenue Storm Drain (“Magnolia Center Outlet”)

No flow connectivity to SAR mainstem due to over ½ mile of floodplain between the outfall and SAR mainstem; may reach SAR if SAR mainstem changes course over time

Phoenix Avenue Storm Drain No flow connectivity to SAR mainstem; over ½ mile of floodplain between the outfall and SAR mainstem; may reach SAR if SAR mainstem changes course over time

Anza Channel (Drain)1 Observed flow connectivity to SAR mainstem

Sunnyslope Channel1 Observed flow connectivity; flow observed from end of lined portion of Sunnyslope Channel to convergence with SAR mainstem

Norco North Sub Drainage D1 Observed no flow at outlet structure; completely dry; distance to mainstem is several hundred feet to the west

Tributary to Cucamonga Creek

Eastvale MDP Line A Directly connected outfall to Cucamonga Creek; observed slight sheet flow into Cucamonga Creek

Eastvale MDP Line B Directly connected outfall to Cucamonga Creek; slight amount of sheet flow Schleishman Road Storm Drain Directly connected outfall to Cucamonga Creek; slight amount of sheet flow

Chandler Street Channel No flow observed, completely dry channel; observation from Hellman Avenue overcrossing

County Line Channel Observed flow downstream to Cucamonga Creek 1 Previous 2007‐08 USEP Monitoring Program site


San Bernardino County MS4 Outfalls/Channel Locations CDM coordinated with SBCFCD staff to identify at least five MS4 outfall/channels to collect dry weather flows. CDM presented for SBCFCD review a recommended list of locations to conduct additional flow measurements. Table 3 summarizes SBCFCD staff observations at outfalls/channels visited on March 30 and April 6, 2011. SBCFCD staff also made visual estimates of flow by conducting windshield surveys of other outfalls in the area.

Table 3. Potential Flow Monitoring Locations, San Bernardino County

MS4 Outfall/Channel Field Observations

Tributary to San Antonio Channel

Chino‐Central Storm Drain Small discharge; drain outlet is at same elevation of channel invert leading to backflow and ponding into drain outlet; accurate flow measurement not possible

Boys Republic South Channel Observed constant flow; invert allows for easier flow measurement

Yorba‐Chino Storm Drain Drain outlet is at same elevation of channel invert leading to backflow and ponding in drain outlet; accurate flow measurement not possible

San Antonio Channel at Riverside Drive Slight flow observed


Cucamonga Creek at Chino Avenue Observed runoff mixes with Inland Empire Utilities Agency recycled water

Airport Drive Storm Drain Storm drain has four separate discharge outlets to the channel; flows to channel observed had shallow depth

Tributary to SAR

San Sevaine Channel at Philadelphia Street DWF with very shallow depth; flows split into different separate ribbons; challenge to collect flow measurement

Based on SBCFCD staff knowledge of typical DWF conditions and field observation, seven MS4 flow locations were selected for DWF measurements (Table 4 and Figure 1). Sites were

Table 2. Selected Flow Monitoring Locations, Riverside County

Flow Site Site Description


US‐BXSP Box Springs Channel at Tequesquite Avenue

US‐SNCH Sunnyslope Channel near confluence with SAR

US‐ANZA Anza Drain upstream of confluence of Riverside effluent channel


US‐CLCH County Line Channel near confluence with Cucamonga Creek

US‐EVLA Eastvale MPD Line A – Outfall discharges to Cucamonga Creek on east side of channel at near 65th Street.

US‐EVLB Eastvale MPD Line B ‐ Outfall discharges to Cucamonga Creek on east side of channel at just downstream of Schleishman Ave overcrossing.

US‐SRSD Schleishman Road Storm Drain ‐ outfall discharges to Cucamonga Creek on west side of channel at Schleishman Road


prioritized based on ability to measure an accurate flow reading. Many outfalls have physical constraints such that flow from the channel backflows into the outfall pipe which makes flow measurements challenging, requiring entry into confined spaces in the outfall pipes.

Table 4. Selected Flow Locations, San Bernardino County

Flow Location Site Description


US‐CUC57 Outfall located upstream of Union Pacific Railroad

US‐CUC25 Outfall located 110‐ft downstream of Riverside Avenue


US‐CHSD Chino Storm Drain at San Antonio Channel

US‐SAC21 Outfall located 1/4 mile downstream of Grand Avenue

US‐BRSC Boys Republic South Channel

US‐SAC13 Outfall located below Pipeline Avenue / State Route 71


US‐SSCH‐PHIL San Sevaine Channel at Philadelphia Street, near county line

2011 Dry Season Flow Monitoring Flow monitoring for the 14 selected MS4 outfalls/channels commenced on April 19 and concluded on June 24, 2011 (Figure 1). In addition to these flow sites, Figure 1 also includes US‐CHINOCRK and US‐BXSP monitoring locations. US‐CHINOCRK was monitored for bacterial indicators and flow as part of a Task 2.2 ‐ Preliminary Characterization of Bacteria Loading in Pomona and Claremont. US‐BXSP was also monitored as part of Task 2.1 – Box Springs Channel Follow‐up Study.

Table 5 lists the combined flow locations in the MSAR watershed located in both San Bernardino and Riverside County jurisdictions. SBCFCD staff recorded flows at seven MS4 outfalls/channels within SBCFCD jurisdiction, while CDM conducted monitoring at seven locations within RCFC&WCD jurisdiction. Flow measurements were collected weekly for ten weeks at varying times and days using methods established in the MSAR Water Quality Monitoring Plan, May 2011.


Figure 1. 2011 Dry Weather Flow Monitoring Locations


2011 Dry Weather Flow Monitoring Results Table 6 shows the range of DWF measurements from all MS4 outfall/channel locations monitored during the 2011 dry weather period. Within the Chino and Cucamonga Creek watersheds, these measurements provide information for MS4 outfalls that were not characterized in the original Urban Source Evaluation Plan (USEP) Monitoring Program (2007‐2008), increasing the monitored urbanized drainage area by 16,800 acres. Figure 2 shows that there are still unmonitored areas for assessment in upcoming years, but that the 2011 dry season provided data for about 40 percent of the MS4 drainage area that was not evaluated in the original USEP Monitoring Program.

Table 6 also estimates the urban runoff generation rate (gal/acre/day) by comparing the median of DWF measurements with the upstream MS4 drainage area. Urban runoff generation rates vary widely between the 2011 dry season monitoring sites. As expected, relatively high rates (> 100 gal/ac/day) were measured at outfalls where SBCFCD and RCFC&WCD staff have observed

Table 5. Flow Locations within MSAR Watershed

Flow Location Site Description


US‐BXSP1 Box Springs Channel at Tequesquite Avenue

US‐SNCH Sunnyslope Channel near confluence with SAR

US‐ANZA Anza Drain upstream of confluence of Riverside effluent channel

US‐SSCH‐PHIL San Sevaine Channel at Philadelphia Street


US‐CUC57 Outfall located upstream of Union Pacific Railroad

US‐CUC25 Outfall located 110‐ft downstream of Riverside Avenue

US‐CLCH County Line Channel above confluence with Cucamonga Creek

US‐EVLA Eastvale MPD Line A – Outfall discharges to Cucamonga Creek on east side of Cucamonga Creek channel south of 65th Street

US‐EVLB Eastvale MPD Line B ‐ Outfall located on east side of Cucamonga Creek channel just downstream of Schleishman Avenue overcrossing

US‐SRSD Schleishman Road Storm Drain ‐ outfall located on west side Cucamonga Creek channel at Schleishman Road

Tributary to Chino Creek

US‐CHINOCRK2 Chino Creek upstream of confluence with San Antonio Channel


US‐CHSD Chino Storm Drain at San Antonio Channel

US‐SAC21 Outfall located 1/4 mile downstream of Grand Avenue

US‐BRSC Boys Republic South Channel

US‐SAC13 Outfall located below Pipeline Avenue / State Route 71 1 US‐BXSP: Initial five weeks of flow measurements collected by RCFC&WCD; latter 5 weeks of flow collected by CDM 2 US‐CHINOCRK: Flow measurements collected as part of Preliminary Characterization of Bacteria Loading from MS4 in Pomona (reported in Task 2.2 Technical Memorandum).


groundwater inputs occur via springs in unlined channels or weep holes in concrete lined channels; such as drainage from Boys Republic South Channel, Chino Creek, Sunnyslope Channel, Box Springs Channel, and Anza Drain. Conversely, several sites with MS4 drainage areas in the Cities of Chino and Ontario had very low rates of urban runoff generation.

Table 6. Flow Results for 2011 Dry Weather Flow Monitoring

Location Dry Weather Flow (cfs) Drainage Area

(acre) Urban Runoff

Rate (gal/ac/day) Min Max Median

Chino Creek at Central Avenue (WW‐C7)

US‐CCCH 2.30 15.31 6.55 1,766 2,396

US‐SACH 0.17 1.25 0.71 5,031 91

US‐CHSD 0.00 0.07 0.015 3,224 3

US‐CHINOCRK 1.12 2.94 1.49 6,036 159

US‐BRSC 0.08 1.08 0.33 1,161 181

US‐SAC21 0.06 0.39 0.09 312 178

US‐SAC13 0.00 0.06 0.01 1,148 5

Cucamonga Creek at Chino Corona Road (WW‐M5)

US‐CHRIS 0.25 1.72 0.79 3,091 165

US‐CLCH 0.00 2.00 0.06 373 95

US‐CUC 1.30 4.63 2.77 602 2,974

US‐CUC57 0.01 0.06 0.02 1,051 13

US‐CUC25 0.001 0.01 0.005 98 33

US‐CLCH 0.00 0.13 0.00 2,474 0

US‐EVLA 0.01 0.19 0.05 499 69

US‐EVLB 0.00 0.01 0.00 335 0

US‐SRSD 0.003 0.09 0.05 463 73

Santa Ana River at MWD Crossing (WW‐S1)

US‐BXSP 0.50 3.66 1.50 5,632 172

US‐SNCH 1.15 3.18 1.96 4,646 273

Santa Ana River at Pedley Ave (WW‐S4)

US‐ANZA 2.12 6.08 2.81 9,268 196

US‐DAY 0.00 4.91 0.52 2,759 122

US‐SSCH 0.00 11.84 1.30 2,489 338

US‐SSCH‐PHIL 0.00 1.75 0.01 788 8

Discussion Based on monitoring data from the watershed‐wide compliance monitoring program and USEP Monitoring Program, the San Bernardino County and Riverside County MS4 Programs have each developed a long term dry weather Comprehensive Bacteria Reduction Plan (CBRP)


designed to achieve compliance with urban wasteload allocations under dry weather conditions. Understanding dry weather hydrology is critical in implementing the CBRP, Attachment B.2 – Dry Weather Hydrology (CBRP, June 28, 2011), evaluates DWFs within the MSAR watershed on a watershed‐wide compliance site basis (please refer to the CBRP for more background discussion). The following section updates findings based on the additional flow monitoring data obtained during the 2011 dry season for each Watershed‐wide compliance monitoring site.

Chino Creek at Central Avenue (WW‐C7) New flow sites at US‐CHINOCRK, US‐BRSC, and US‐SAC21 have urban runoff generation rates ranging from 159 to 178 gal/acre/day (Table 6). DWF from the drainage areas upstream of these sites is higher than was assumed (100 gal/ac/day) in the CBRP. The US‐CHINOCRK site captures DWF from most of the City of Pomona’s drainage area within the MSAR watershed. DWF measured at this site ranged from 1.1 to 3.0 cfs, with a median of 1.5 cfs, which equates to approximately 15 percent of the DWF from the MS4 to Chino Creek.

Figure 2. Coverage of DWF Assessment for all Urban Landuse within Hydrologically Connected MS4 Drainage Area within the MSAR Watershed (post 2007 USEP Monitoring Program; post 2011

29,400

36,600

18,000

10,800

0

10,000

20,000

30,000

40,000

50,000

60,000

USEP Monitoring Program 2011 Monitoring

Urban

Land Use within Hydrologically

Con

nected

MS4 Drainages

(acres)

Unmonitored Urban Land Urban Land Upstream of DWF Monitoring Locations


Mill‐Cucamonga Creek at Chino Corona Road (WW‐M5) The results from 2011 DWF monitoring sites upstream of this watershed‐wide compliance site show that these outfalls (US‐CUC57, US‐CUC25, US‐ CLCH, US‐EVLA, US‐EVLB, and US‐SRSD) contribute very small volumes (<0.05 cfs) of DWF to Cucamonga Creek. DWF at US‐CLCH in 2007 was 0.06 cfs (median), which was similar to median DWFs in 2011 from other MS4 outfalls to Cucamonga Creek. DWF from US‐CHRIS in 2007 was 0.79 (median) and is therefore a more significant source of urban DWF to Cucamonga Creek than other monitored outfalls.

In 2011, DWF measurements were taken at US‐CUC57, which discharges to the segment of Cucamonga Creek downstream of the Turner Basins and upstream of the US‐CUC site. DWF measurements showed very low DWF (median of 0.02 cfs). In addition, SBCFCD windshield surveys evaluated all 36” diameter and larger outfalls in this segment of Cucamonga Creek. These surveys identified only minimal additional DWF, which could not explain the DWF in Cucamonga Creek above RP1. Therefore, DWF in Cucamonga Creek above RP1 is most likely from MS4 discharges that bypass or flow through the Turner Basins. IEUA is currently developing a project to improve operations at the Turner Basins, which will improve the capacity to capture urban DWF from Upper Deer and Cucamonga Creeks.

Santa Ana River at MWD Crossing (WW‐S1) Sources of urban runoff to the Santa Ana River at MWD Crossing during the dry season are limited to two key tributaries; Sunnyslope Channel and Box Springs Channel. In 2011, DWF at US‐SNCH was 1.96 cfs (median) compared to 2.9 cfs in 2007. For US‐BXSP, median DWF was 1.50 cfs compared to 3.33 cfs in 2007.

CDM and RCFC&WCD conducted field observations of other potential MS4 discharges to the Santa Ana River upstream of the MWD Crossing site on March 17, 2011. With one exception, no measurable DWF was observed to connect to the Santa Ana River from other MS4 drainages in this watershed including High Grove Channel, Agua Mansa Storm Drain, Phoenix Storm Drain, and a few other minor outfalls along the north side of the river. For Magnolia Storm Drain, significant DWF was observed at the outfall; however the distance from the MS4 outfall to the mainstem of the SAR is approximately one‐half mile, over which recharge into the river bottom sediment occurs. Observations at Magnolia Storm Drain and other MS4 outfalls should continue to assess DWF connectivity or confirm that the lack of DWF is consistent.

Santa Ana River at Pedley Avenue (WW‐S4) In the 2011 dry season, DWF measurements were recorded for the Anza Drain tributary to the Santa Ana River at a location ~1,000 feet upstream of the US‐ANZA site from the 2007 USEP Monitoring Program which resulted in a negligible increase in upstream drainage area . The new site facilitated access to a larger cross‐sectional area with unobstructed flow, where more measurements were recorded in developing a velocity profile. The 2011 DWF measurements result in a reduced DWF estimate for Anza Drain (from 6.3 cfs in 2007 to 2.8 cfs in 2011). This revised flow is more comparable to measurements taken during a single day field survey in 2002


by RCFC&WCD1, which suggested DWF flows to be is less than 1.5 cfs. Other sources of urban DWF from MS4s in this watershed include San Sevaine Channel and Day Creek. SBCFCD field observations for the 2011 dry season included 10 visits to San Sevaine Channel at the county line near Philadelphia Street (US‐SSCH‐PHIL). Most of San Sevaine Channel within San Bernardino County is upstream of the Jurupa and Declez Basins, where urban DWF is spread for groundwater recharge. At the US‐SSCH‐PHIL site, one flow reading was particularly high (1.75 cfs in early June 2011) compared to the average of less than 0.02 cfs for the remaining weeks. The field observations confirm that DWF is effectively captured in Jurupa Basin and that MS4 outfalls between the Jurupa Basin and county line generate minimal DWF (<0.05 cfs). The remainder of flow in San Sevaine Channel that reaches the Santa Ana River comes from MS4 outfalls in the City of Jurupa Valley or non‐urban discharges.

Field observations of other potential MS4 discharges to the Santa Ana River upstream of the Pedley Avenue site were conducted on March 17, 2011 by CDM and RCFC&WCD. During these field observations, no measurable DWF was observed from any other sites in this watershed. Observations at these outfalls should continue to confirm that the lack of DWF is consistent.

Summary of Findings Additional DWF measurements taken at existing and new urban source evaluation sites showed that urban runoff generation was less than the assumed value of 100 gal/ac/day for unmonitored outfalls in the assessment of urban sources from the 2007 USEP Monitoring Program, except in the Chino Creek watershed. The data collected in the 2011 dry season was used to revise the bacterial indicator source contribution analysis, as described in the Technical Memorandum for Task 2.4, Calculate Mass Balance for Dry Weather Conditions.

Analysis of Variability of Dry Weather Flow Additional DWF measurements were taken at Anza Drain, Box Springs Channel, and Sunnyslope Channel. These measurements increase the robustness of DWF estimates at these tributaries from the MS4 to the Santa Ana River. In the case of Anza Drain, the measurements taken in the 2011 dry season were significantly lower than from the 2007 dry season. In 2011, a new field method was employed to measure flow. The new method involved moving the cross section for determining a velocity profile by ~200 ft to a location with more uniform flow and better access, which allowed for velocity readings at more intervals across the section. Therefore the dataset was reduced to the ten measurements from the 2011 dry season.

For Sunnyslope Channel, the data collected in the 2011 dry season increases the DWF dataset from 10 to 20 measurements. The coefficient of variation from the 2007‐2008 USEP Monitoring Program and 2011 dry season measurements was relatively low; therefore, additional measurements at this site are not a high priority.

1 RCFC&WCD staff, Clark and Clem, conducted flow field survey at Anza Drain in 2002.


Increasing the number of flow observations at dry outfalls in the MSAR provides additional statistical power to assessments of water balance at watershed‐wide compliance sites during dry weather conditions. Power analysis is suited for naturally occurring variables, and therefore is not applied to approximate level of monitoring activities for variables that are controlled by human behavior. Urban DWF in the MSAR watershed is primarily controlled by human behavior. Sources range from actions by individuals that are relatively small but widespread such as illicit discharges and excess outdoor water use, to relatively high volume inputs at specific points by water and wastewater agencies such as tertiary treated effluent from POTWs, imported water turnouts, other water transfers, and temporary de‐minimus discharges.

One important consideration in developing outfall monitoring programs is the diurnal pattern of outdoor water use. Accordingly, the CBRP Inspection Program includes assessment of DWF during different times of day as well as seasons to account for variability associated with diurnal outdoor water use patterns in the watershed. Data obtained from the CBRP Inspection Program will continue to be evaluated to understand specific sources of DWF in MS4 drainage areas in order to select appropriate controls for prioritized outfalls based on source contribution analysis.

Attachment D

Calculate Mass Balance for Dry Weather Conditions (Task 2.4)

Memorandum To: Rick Whetsel, SAWPA From: Richard Meyerhoff, CDM Steven Wolosoff, CDM Date: August 12, 2011 Subject: Source Evaluation ‐ Task 2.4 Dry Weather Bacterial Indicator Mass Balance

The role of discharges from municipal separate storm sewers systems (MS4s) in receiving water bacterial quality was evaluated in the USEP Study in the dry seasons of 2007 and 2008. Generally, this characterization provided monitoring data from most urban drainages upstream of watershed wide TMDL compliance monitoring sites. The Comprehensive Bacteria Reduction Plan (CBRP) synthesized these data to approximate the bacterial indicator source contribution from MS4s for each of the Middle Santa Ana River (MSAR) Bacteria TMDL compliance monitoring sites.

In the dry season of 2011, additional dry season bacterial indicator and flowrate data were collected at key MS4 outfalls that were not monitored as part of the original USEP Study or where additional data was needed to support source characterization. This technical memorandum updates the MSAR bacterial indicator source contribution analysis for average dry season conditions based on the results of 2011 dry season source evaluation monitoring activities. The original data for this analysis are summarized in the CBRP. New data used incorporated into this updated analysis are described in the following technical memoranda:

Source Evaluation Task 2.1 Box Springs Channel Follow‐up Study

Source Evaluation Task 2.2 Preliminary Characterization of Bacteria Loading in Pomona And Claremont

Source Evaluation Task 2.3 Survey of Dry Weather Flows from MS4 Outfalls to Major Tributaries.

Data Summary

For each of the 2007‐2008 USEP Study sites, data were collected for dry weather flow (DWF) rates and bacterial indicator concentration. In the 2011 dry season, follow up DWF measurements were performed at Anza Drain (US‐ANZA), Box Springs Channel (US‐BXSP), County Line Channel (US‐CLCH), and Sunnyslope Channel (US‐SNCH). In addition, DFW

Dry Weather Bacterial Indicator Mass Balance August 12, 2011 Page 2

measurements were collected at nine new outfalls from MS4 systems in both San Bernardino and Riverside Counties to receiving waterbodies (Figure 1).

While DWF measurements were recorded weekly for 10 weeks in the 2011 dry season, bacterial indicator samples were only collected at two sites; Box Spring Channel (US‐BXSP) and Chino Creek above San Antonio Creek (CHINOCRK). To allow for estimation of bacterial indicator loads to receiving waterbodies, the median E. coli concentration from all source evaluation monitoring samples in the MSAR watershed from the 2007 and 2011 dry seasons (560 cfu/100 mL) was assumed for MS4 systems discharges without any data.

Source Contribution Analysis Relative source contribution analyses were prepared for each of the watershed‐wide compliance locations. This analysis provided a comparison of monitored inputs of DWF (Qinflow) and

Figure 1. 2011 Dry Season DWF and Bacterial Water Quality Monitoring Sites


bacterial indicator concentrations (Cinflow) from MS4 facilities and POTWs with downstream flow (Qcomp) and bacterial indicator concentrations (Ccomp), as follows:

This type of analysis characterizes the relative role of different flow sources in the watershed on downstream bacterial indicator concentrations. An important outcome of this analysis is the identification of the level of bacterial indicators (e) at the compliance locations that cannot be explained by known DWF sources within the watershed (referred to as “unaccounted‐for sources”). The presence of an unbalanced set of inputs and outputs in relation to downstream bacterial indicator levels is not surprising, given the potential for increases in bacteria indicator levels from illegal and illicit discharges, direct input from wildlife, air deposition, transient encampments, environmental growth, or resuspension, or decreases in bacterial indicator levels due to environmental decay or settling.

Source Contribution Results Table 1 provides the average DWF (column 2) and bacteria concentrations (column 3) used to estimate E. coli loads (column 4) from MS4 drainages and total loads at downstream compliance monitoring sites. The difference between loads from urban source evaluation sites and watershed wide TMDL compliance sites approximates the contribution of MS4s discharges to receiving water impairments relative to other unaccounted‐for sources of bacterial indicators. This table is equivalent to Table 3‐2 in the CBRP. Highlighted cells indicate data that were updated based on source evaluation activities completed during the 2011 dry season.

The relative source contribution analysis shows high amounts of unaccounted‐for bacterial indicators at all four compliance points during DWF in the dry season (Figure 2). The following sections discuss the findings of the this analysis and remaining data gaps specific to each watershed‐wide compliance monitoring location.

The relative source contribution analysis shows high amounts of unaccounted‐for bacterial indicators at all four compliance points during DWF in the dry season (Figure 2). The following sections discuss the findings of the this analysis and remaining data gaps specific to each watershed‐wide compliance monitoring location.


Table 1. Source Contribution Analysis for E. coli in Dry Season for Each Watershed Wide Bacterial Indicator TMDL Compliance Site in the MSAR Watershed

Site Hydrologically Connected MS4

Acres

Dry Weather Runoff (cfs)

Dry Weather Geometric Mean of E.

coli (cfu/100ml)

Dry Weather E. coli

(cfu/day)

Santa Ana River at MWD Crossing (WW‐S1) 6,297 73.2 149 265

POTW Influent n/a 68.7 2 4

USEP SNCH 2,104 2.0 183 9

USEP BXSP 4,193 1.8 1,549 69

MS4 Runoff 4.5 78

Unaccounted‐for Sources 183

Santa Ana River at Pedley Ave (WW‐S4) 17,921 55.5 149 202


USEP ANZA 6,335 3.3 492 38

USEP DAY 2,759 0.5 577 7

USEP SSCH 2,489 1.3 320 10

Other MS4 Areas 1 6,338 1.0 560 2 13

MS4 Runoff 6.1 69


Chino Creek at Central Ave (WW‐C7) 17,678 19.0 394 183

POTW Influent n/a 8.8 2 0.5

USEP CCCH 1,766 6.5 61 10

USEP SACH 5,031 0.7 412 7

CHINOCRK 4,357 1.7 499 21

BRSC 707 0.4 560 2 5

SAC13 1,080 0.02 560 2 0

SAC 21 266 0.1 560 2 2

Other MS4 Areas 1 4,472 0.7 560 2 9

MS4 Runoff 10.2 54


Mill Creek at Chino Corona Rd (WW‐M5) 5,510 30.9 877 663


USEP CHRIS 3,091 0.8 868 17

USEP CLCH 373 0.1 1,194 2

USEP CUC 602 2.8 139 9

CUC57 760 0.02 560 2 0

CUC25 38 0.01 560 2 0

EVLA 184 0.1 560 2 1

EVLB 45 0.004 560 2 0

SRSD 417 0.1 560 2 1

MS4 Runoff 3.8 30


1) Other MS4 areas include all MS4 outfalls to receiving waterbodies where DWF measurements have not been recorded. For these areas, the source contribution analysis assumed a DWF generation rate of 100 gallons per day per acre of urbanized land use. DWF and bacterial indicator concentrations for these areas will be evaluated through CBRP source evaluation activities prior to 2015 and IDDE programs. 2) Median of all 2007 and 2011 dry season E. coli samples from MS4 systems


Santa Ana River at MWD Crossing Sources of urban runoff to the Santa Ana River at MWD Crossing during the dry season are limited to two key tributaries; Sunnyslope Channel and Box Springs Channel. Sunnyslope Channel DWF includes mostly rising groundwater and therefore has significantly lower E. coli concentrations than other USEP sites. Conversely, Box Springs Channel was the single highest priority site based on ranking from the 2007 USEP Study. One of the reasons for this was the presence of human source bacteria in the majority of samples collected in 2007. In 2008, Riverside County Flood Control and Water Conservation District (RCFC&WCD) and the City of Riverside discovered that a single restroom toilet located in the Sam Evans Sports Complex on the Riverside Community College (RCC) Campus was inadvertently connected to a storm drain pipe rather than a sewer line. Data collected after the elimination of this source of bacteria in Box Springs Channel indicated the elimination of human polymerase chain reaction (PCR) markers in runoff from Box Springs Channel. Despite this correction, follow up monitoring of bacterial indicators at Box Springs Channel in the 2011 dry season showed that this MS4 drainage area remains to be a high priority for non‐human bacterial indicators.

Field observations of other potential MS4 discharges to the Santa Ana River upstream of the MWD Crossing site were conducted on March 17, 2011 by CDM and RCFC&WCD. With one

29% 34% 30% 4%

71%66%

70%

96%

0

100

200

300

400

500

600

700

Santa Ana River at MWD Crossing (WW‐S1)

Santa Ana River at Pedley Ave (WW‐S4)

Chino Creek at Central Ave (WW‐C7)

Mill Creek at Chino Corona Rd (WW‐M5)

E. coli (billion cfu/day)

Unaccounted‐for Sources

MS4 Dry Weather Flow

Figure 2. Relative Contribution of Bacterial Indicators from MS4 Discharges to Total Downstream Loading


exception, these observations found no measurable DWF was observed to connect to the Santa Ana River from other MS4 drainages in this watershed including High Grove Channel, Agua Mansa Storm Drain, Phoenix Storm Drain, and a few other minor outfalls along the north side of the river. For Magnolia Storm Drain, significant DWF was observed at the outfall; however the distance from the MS4 outfall to the mainstem of the SAR is approximately one‐half mile, over which recharge into the river bottom sediment may occur. Observations at Magnolia Storm Drain and other MS4 outfalls should continue to assess DWF connectivity or confirm that the lack of DWF is consistent.

Santa Ana River at Pedley Avenue In the 2011 dry season, DWF measurements were recorded for the Anza Drain tributary to the Santa Ana River. The cross section used to collect the flow measurement allowed for a more accurate reading than was obtained in 2007 during the original USEP Study. Reduced estimates of DWF from Anza Drain (from 6.3 cfs in 2007 to 3.2 cfs in 2011) resulted in a reduction in the urban MS4 source contribution to E. coli loads in the Santa Ana River.

Other sources of urban DWF from MS4s in this watershed include San Sevaine Channel and Day Creek. San Bernardino County Flood Control District (SBCFCD) field observations for the 2011 dry season included 10 visits to San Sevaine Channel at the county line. Most of San Sevaine Channel within San Bernardino County is upstream of the Jurupa Basin, where urban DWF is spread for groundwater recharge. The field observations confirm that DWF is effectively captured in Jurupa Basin and that MS4 outfalls between the Jurupa Basin and county line generate minimal DWF during typical operating conditions (<0.05 cfs).

Field observations of other potential MS4 discharges to the Santa Ana River upstream of the Pedley Avenue site were conducted on March 17, 2011 by CDM and RCFC&WCD. During these field observations, no measurable DWF was observed from any other MS4 outfalls in this watershed. Observations at these MS4 outfalls should continue to confirm that the lack of DWF is consistent.

Mill-Cucamonga Creek at Chino Corona Road Mill‐Cucamonga Creek has the largest fraction of unaccounted for bacteria of the impaired waterbodies in the MSAR watershed. Additional DWF measurements of outfalls to Cucamonga Creek were conducted in the 2011 dry season to characterize outfalls that were not assessed in the 2007 dry season USEP Study. Weekly DWF measurements at five key MS4 outfalls (EVLA, EVLB, SRSD, CUC 25, and CUC57) downstream of the Turner Basins were recorded for 10 consecutive weeks. The results showed that these outfalls contribute less than expected volumes of DWF to Cucamonga Creek, thus the unaccounted‐for source of bacterial indicators in this watershed may not be attributable to previously unmonitored MS4 discharges.

The 2007 dry season DWF measurements at US‐CUC (Cucamonga Creek above RP1) are high relative to expected DWF generation rates, if all MS4 drainage areas upstream of the Turner Basins are hydrologically disconnected. Thus, it was important to assess MS4 sources to


Cucamonga Creek downstream of the Turner Basins, largely between Highway 10 and Highway 60 in the City of Ontario. In 2011, DWF measurements were taken at a MS4 outfall, which discharge to this segment of Cucamonga Creek (CUC57). DWF measurements at this outfall showed very low DWF (average of 0.02 cfs). In addition, SBCFCD windshield surveys evaluated all 36” diameter and larger outfalls in this segment of Cucamonga Creek. These surveys identified only minimal additional DWF, which could not explain the DWF in Cucamonga Creek above RP1. Therefore, DWF in Cucamonga Creek above RP1 is most likely from MS4 discharges that bypass or flow through the Turner Basins. Inland Empire Utilities Agency is currently developing a project to improve operations at the Turner Basins, which will improve the capacity to capture urban DWF from Upper Deer and Cucamonga Creeks. It is important to note that reducing DWF in Cucamonga Creek above RP1 will only address the portion of downstream bacteria loads that could be attributed to MS4 discharges (~5 percent). Source evaluation activities included in the CBRP will attempt to characterize the unaccounted‐for fraction of bacterial indicators, which are the predominant cause for non‐compliance.

Chino Creek at Central Avenue In the Chino Creek watershed, there were several key tributaries that were not monitored during the 2007 dry season USEP Study. New data obtained in the dry season of 2011 improved the characterization of urban DWF and bacterial indicators in this watershed. DWF measurements and bacterial indicator samples were collected from Chino Creek upstream of the San Antonio Creek confluence (CHINOCRK). This tributary captures DWF from most of the City of Pomona’s MS4 drainage area within the MSAR watershed. The data indicate an average E. coli concentration of 500 cfu/100, which is comparable to the assumed concentration used in previous source contribution analyses. DWF measurements were also taken in a major MS4 outfall to San Antonio Creek, which also includes drainage from the City of Pomona. With an assumed E. coli concentration for this MS4 discharge of 500 cfu/100mL (median of all 2007 and 2011 dry season samples from MS4 systems), the combined loading from City of Pomona accounts for approximately 40 percent of all E. coli loads attributed to urban DWF sources in the Chino Creek watershed.

Other DWF measurements during the 2011 dry season increased source contribution analysis input data for MS4 discharge to Chino Creek. Accordingly, the relative role of MS4 sources to bacterial indicator loads in Chino Creek at Central is greater than approximated in the CBRP, increasing the estimated contribution of E. coli loads from MS4s to 30 percent.

Summary of Findings DWF measurements and windshield surveys, and bacterial water quality samples collected in the 2011 dry season provided some key information necessary to understand the sources of bacterial indicators in the MSAR watershed. Each of the following findings characterizes specific MS4 drainage areas and will be used to guide future source evaluation activities to be completed as part of CBRP implementation:


Non‐human sources of bacterial indicators at Box Springs Channel are a high priority in the Santa Ana River at MWD Crossing watershed.

DWF from the Anza Drain MS4 drainage area is 50 percent less than measured in the 2007 dry season. Flow measurements taken in the 2011 dry season involved an improved approach, using a better cross section and more readings in developing a cross‐sectional velocity profile to compute flowrate. Consequently, MS4s have reduced relative source contribution to total bacterial loads in the Santa Ana River at Pedley Avenue watershed.

DWF measurements and windshield surveys suggest that unaccounted‐for bacterial indicator loads may be predominantly from non‐urban sources in the Mill‐Cucamonga Creek at Chino Corona Rd watershed.

The Turner Basins do not typically capture 100 percent of DWF from the Upper Deer and Cucamonga Creek watersheds.

Approximately 40 percent of the bacterial load in the Chino Creek watershed could be attributed to MS4 discharges from the City of Pomona.

Attachment E

Calculate Site-Specific Log Standard Deviation at Monitoring Sites (Task 2.5)

Memorandum To: SAWPA From: CDM Date: September 14, 2011 Subject: Source Evaluation Task 2.5 ‐ Site‐Specific Log Standard Deviation at Middle

Santa Ana River Watershed Monitoring Sites

Task Overview Antidegradation policy in the Clean Water Act requires that existing beneficial uses in all Waters of the US be protected by ensuring that water quality is maintained at levels sufficient to support such uses. Two methods for evaluating water quality monitoring data to assess whether antidegradation policy is achieved for bacterial water quality in the MSAR watershed were implemented as described in the following sections.

Single Sample Maximum Criteria The EPA uses a default log standard deviation (LSD) of 0.4 for E. coli when calculating single sample maximum criteria. A local log standard deviation may be substituted for the default value where such data exist, which would result in different single sample maximum criteria. The potential to use a site‐specific log standard deviation to establish site‐specific single sample criteria has been incorporated into the Basin Plan amendment under development by the Stormwater Quality Standards Task Force. The purpose of this task is to calculate site‐specific criteria for antidegradation objectives for waterbodies in the MSAR watershed. Sites included in this analysis include the five watershed‐wide TMDL compliance monitoring sites (sampled regularly since 2007), major tributaries sampled in the 2007‐2008 Urban Source Evaluation Plan (USEP) Monitoring Program1, and one new urban source evaluation monitoring site sampled during the 2011 dry season (see Source Evaluation Task 2.2 Preliminary Characterization of Bacteria Loading in Pomona and Claremont).

Table 1 shows the geometric mean, 95th percentile, and potential antidegradation objectives based on the default LSD of 0.4 and site specific LSD for dry season E. coli for each site.

1 SAWPA. 2008. Middle Santa Ana River Water Quality Monitoring Plan. Prepared by CDM on behalf of SAWPA and the Middle Santa Ana River Watershed TMDL Task Force. April, 2008.

SAWPA September 14, 2011 Page 2

The EPA Procedure for Estimating the Maximum Expected Concentration2 estimates site‐specific alternative single sample maximums for each site. This method assigns the 95th or 99th percentile of the fitted lognormal distribution as the single sample maximum. As shown in Figure 1, for sites with robust datasets (n > 100 for the five watershed‐wide TMDL compliance sites), the 95th percentile of the data is similar to the 95th percentile of the lognormal distribution, because the data fit a lognormal distribution.

2 EPA, 1991. Technical Support Document for Water Quality Based Toxics Control. Report EPA/505/2-90-001

Table 1. Single Sample Maximum Criteria for E. coli at USEP and Watershed‐Wide Monitoring Sites

Site Name Number of Samples 1

95th Percentile of Dry Weather E. coli Samples

(cfu/100 mL)

95th Percentile of Lognormal Dist. With LSD of 0.4 (cfu/100 mL)

95th Percentile of Lognormal Dist. with Site Specific LSD (cfu/100 mL)

Urban Source Evaluation Sites

US‐ANZA 18 5,565 663 2,790

US‐BXSP 23 5,910 2,487 19,056

US‐CCCH 19 590 190 854

US‐CHINOCRK 10 1,411 1,034 2,526

US‐CHRIS 18 4,600 2,087 7,415

US‐CLCH 7 8,170 1,498 43,612

US‐CUC 19 3,930 367 6,264

US‐CYP 12 32,625 5,204 17,699

US‐DAY 13 6,200 902 3,977

US‐SACH 18 4,205 739 8,838

US‐SAR 5 6,360 1,792 21,725

US‐SNCH 19 1,546 284 1,481

US‐SSCH 14 4,090 704 6,086

US‐TEM1 18 1,180 691 1,644

Watershed‐wide TMDL Compliance Monitoring Sites

WW‐C3 131 740 230 688

WW‐C7 128 1,929 624 1,563

WW‐M5 127 3,380 1,180 3,537

WW‐S1 125 400 263 510

WW‐S4 123 489 263 474 1 Outlier sample collected from Temescal Creek on 9/8/2007 was removed


Maximum Expected Geometric Mean Single sample criteria provide limited benefit for evaluation of potential degradation, because of the inherent sample‐to‐sample variability in bacterial indicators concentration. One alternative to using a single sample maximum objective is to use a maximum expected geometric mean. Land’s Method3 was applied to estimate the 95th percentile upper confidence limit for the geometric mean). When calculating geometric means based on new data, it is improbable that they would exceed the 95th percentile upper confidence limit, unless bacterial indicator quality was degraded. Table 2 summarizes the results of this analysis for all dry weather E. coli samples from USEP and watershed–wide TMDL compliance monitoring sites. The difference between the geometric mean of historical data and the maximum expected geometric mean is a function of the number of samples and variability of the original dataset. EPA’s guidance document recommends that caution be used when applying this method because it is sensitive to potential outliers. Results shown for the USEP Study monitoring sites show that this method does not produce valuable results given the small dataset (n < 20) and higher variability (LSD > 3.0), therefore it is only recommended that this antidegradation objective be considered for the watershed‐wide TMDL compliance monitoring sites. Figure 2 compares geometric means and 3 EPA, 1991. Technical Support Document for Water Quality Based Toxics Control. Report EPA/505/2-90-001

‐

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

Prado Park Lake at Lake Outlet

Chino Creek at Central Avenue

Mill Creek at Chino‐Corona Rd

Santa Ana River Reach 3 @ MWD

Crossing

Santa Ana River Reach 3 @ Hamner

Ave

E. coli (cfu/10

0mL)

95th Percentile ‐ Raw Data

95th Percentile ‐ Lognormal Dist

Figure 1. Comparison of 95th Percentile of E. coli Data with 95th Percentile of Lognormal Distribution (Site Specific Single Sample Maximum Criteria)


95th percentile upper confidence limits for geometrics means for each watershed‐wide monitoring site. The site with the greatest variability, Mill‐Cucamonga Creek at Chino‐Corona Road, has the greatest relative difference between the historical geometric mean and the 95th percentile upper confidence limit.

Table 2. Maximum Geometric Mean Criteria for E. coli at USEP Study and Watershed‐Wide TMDL Compliance Monitoring Sites

Site Name Number of Samples 1

Geometric Mean (cfu/100 mL)

95th Percentile Upper Confidence Limit for Geometric Mean (cfu/100

mL)

US‐ANZA 18 343 1,952

US‐BXSP 23 1,302 16,720

US‐CCCH 19 99 590

US‐CHINOCRK 10 613 2,145

US‐CHRIS 18 1,081 5,027

US‐CLCH 7 776 65,180,370

US‐CUC 19 190 16,467

US‐CYP 12 2,695 15,640

US‐DAY 13 467 3,769

US‐SACH 18 382 17,315

US‐SAR 5 928 47,647,003

US‐SNCH 19 147 1,255

US‐SSCH 14 364 11,038

US‐TEM1 18 358 1,952

WW‐C3 131 119 272

WW‐C7 128 323 1,383

WW‐M5 127 611 2,268

WW‐S1 125 136 415

WW‐S4 123 136 461

1 Outlier sample collected from Temescal Creek on 9/8/2007 were removed


‐

200

400

600

800

1,000

1,200

1,400

Prado Park Lake at Lake Outlet

Chino Creek at Central Avenue

Mill Creek at Chino‐Corona Rd

Santa Ana River Reach 3 @ MWD

Crossing

Santa Ana River Reach 3 @ Hamner

Ave

E. coli (cfu/10

0mL)

Geomean

95th Percentile Upper Confidence Limit for Geomean

Figure 2. Comparison of Geometric Mean of Historical E. coli Data with 95th Percentile Upper Confidence Limit for Geometric Mean

Documents

Final Submittal Source Evaluation Project Activities€¦ · Subject: Final Submittal ‐ Source Evaluation Project Activities for Middle Santa Ana River, TMDL Program Support 2010‐2011